Fractional statistics in anyon collisions.

Bartolomei, H; Kumar, M; Bisognin, R; Marguerite, A; Berroir, J-M; Bocquillon, E; Plaçais, B; Cavanna, A et al. · Science · 2020

basic_science · Level V

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Abstract

Two-dimensional systems can host exotic particles called anyons whose quantum statistics are neither bosonic nor fermionic. For example, the elementary excitations of the fractional quantum Hall effect at filling factor ν = 1/<i>m</i> (where <i>m</i> is an odd integer) have been predicted to obey Abelian fractional statistics, with a phase ϕ associated with the exchange of two particles equal to π/<i>m</i> However, despite numerous experimental attempts, clear signatures of fractional statistics have remained elusive. We experimentally demonstrate Abelian fractional statistics at filling factor ν = ⅓ by measuring the current correlations resulting from the collision between anyons at a beamsplitter. By analyzing their dependence on the anyon current impinging on the splitter and comparing with recent theoretical models, we extract ϕ = π/3, in agreement with predictions.